Cleaning apparatus for insulating surfaces

ABSTRACT

Apparatus for cleaning residual particulate material remaining after transfer of a developed image from an insulator. The apparatus comprises rotating and stationary brushes for cleaning both surfaces of the insulator, both brushes enmeshing after the cleaning cycle to provide a brush self-cleaning action for the stationary brush. The apparatus is designed such that air flow is at a maximum at the point where the particulate material would normally be centrifuged out of the brush housing, thereby minimizing leakage of the particulate material despite a gap between the insulator and the brush housing.

United States Patent [1 1 Becker et alt 1 CLEANING APPARATUS FOR INSULATING SURFACES [75] Inventors: Gunter E. Becker, Manhattan Beach; Joseph F. Santoro, Glendora,

both of Calif.

[73] Assignee: Xerox Corporation, Stamford,

Conn.

[22] Filed: July 2, 1971 [21] Appl.No.: 159,315

[52] U.S. Cl 15/308, 15/38, 15/77, 15/306 B, 15/364 [51] Int. Cl. A471 5/38, A471 9/04 [58] Field of Search 15/38, 77, 306 A [56'] References Cited UNITED STATES PATENTS 2,358,334 9/1944 Knowlton 15/308 X 2,015,583 9/1935 Bartsch l5/308 568,958 10/1896 Robertson... 15/38 X 1,483,966 2/1924 Collins 15/311 X [111 3,766,593 [4 1 Oct. 23, 1973 FOREIGN PATENTS OR APPLICATIONS 629,418 4/1936 Germany ..15/308 1,134,990 12/1956 France ..15/77 Primary ExaminerWayne A. Morse, Jr. Assistant Examiner-C. K. Moore Attorney-James J. Ralabate et al.

[57] ABSTRACT Apparatus for cleaning residual particulate material remaining after transfer of a developed image from an insulator. The apparatus comprises rotating and stationary brushes for cleaning both surfaces of the insulator, both brushes enmeshing after the cleaning cycle to provide a brush self-cleaning action for the stationary brush. The apparatus is designed such that air flow is at a maximum at the point where the particulate material would normally be centrifuged out of the brush housing, thereby minimizing leakage of the particulate material despite a gap between the insulator and the brush housing.

5 Claims, 2 Drawing Figures PATENIEDnm 23 I973 INVENTORS JOSEPH F. SANTORO GUNTER E. BECKER p v fl I l l I IllIlIlI/llllfllllllflllllllllllI/IIA TTOR/VEY CLEANING APPARATUS FOR INSULATING SURFACES BACKGROUND OF THE INVENTION Techniques for removing residual electrostatically adhering powder particles from an insulating surface are known in the prior art. For example, a xerographic reproducing apparatus is disclosed in U. S. Pat. No. 3,236,165 which utilizes a reusable photoconductive surface formed in the shape of a rotating drum and a toner removal portion (purge system) designed to operate against such a rotating drum. However, the removal problem becomes more acute when the photoconductive surface is in the form of a straight plate. The use of a straight plate causes problems since this feature requires that the plate enter and leave the purge system for subsequent reuse thus leaving an opening from which removed powder particles may escape and contaminate the interior of the system which incorporates the purge system.

U. S. Pat. No. 2,832,977 discloses a device for cleaning powder particles remaining after transfer of a developed image from the surface of a flat plate. However, the problem of powder contamination still is present. In addition, no provision is made for cleaning the opposite side of the flat plate if required.

SUMMARY OF THE PRESENT INVENTION The present invention provides novel apparatus for removing residual particulate material after image transfer from the surface of an insulator. In particular, the apparatus comprises a rotating cylindrical brush, a duct system and a blower which generates the required vacuum. The brush housing is designed in such a way that air flow is at a maximum at the point where the powder, or toner, particles would normally be centrifuged out of the purge system, i.e., at the plate entrance to the cleaningapparatus. As a result of this, toner leakage is minimized despite a gap between the plate and brush housing. A cover on top of the brush housing is cammed upwards as the leading edge of the plate enters and is pulled downwards as the trailing edge leaves. The cover serves to hold a stationary brush that keeps the back of the plate from building up toner over repeated cycles and acts as a shield against toner contamination. The toner being built up on the stationary brush is cleaned out by the rotating brush as both brushes enmesh after the plate leaves the brush housing. With this technique, self cleaning action without an additional cleaning mechanism is achieved.

It is an object of the present invention to provide improved apparatus for cleaning residual toner from an insulating surface after transfer of the developed image.

It is a further object of the present invention to provide a cleaning system which cleans residual toner from the surface of a photoconductor shaped in the form of a flat plate.

It is still a further object of the present invention to provide improved apparatus for cleaning residual toner from the surface of a photoconductor formed in the shape of a flat plate whereby the toner contamination of the interior of the system incorporating the cleaning apparatus is minimized.

DESCRIPTION OF THE DRAWING For a better understanding of the invention as well as LII other objects and features thereof, reference is made to the following description which is to be read in conjunction with the accompanying drawings wherein:

FIG. 1 is a side elevation in section of the cleaning apparatus of the present invention before and after an insulating surface containing residual toner thereon is introduced into the cleaning apparatus; and

FIG. 2 is a side elevation in section of the cleaning apparatus of the present invention with the insulating surface containing residual toner in the process of being cleaned by said apparatus.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to FIG. 1, an insulating surface to be cleaned, such as xerographic plate 10, is shown being transported in the direction of arrow 16 to the novel cleaning apparatus of the present invention. The cleaning apparatus comprises a rotatable cylindrical member or brush 12 having hair, fibers or the like on its outer surface, the brush optionally being retractable into and out of contact with plate 10. The brush housing 14 comprises a cylindrically shaped portion and upper flat portions 30 which at least partially surround the brush I2 and preferably terminates a short distance below the plate. A vacuum or other air flow line leads from the housing 14 to an externally positioned vacuum source or blower (not shown). Drive means are operable to cause the brush l2 and the plate 10 to undergo relative motion, for example, driving plate 12 in the direction shown by arrow 16 and to rotate the brush in the direction shown by arrow 18. Feed rolls 15 and 17 feed plate 10 in the direction of arrow 16. Positioned above the back surface 11 of plate 10 is a housing 20 which includes a lid or cover portion-22. A stationary brush 24 is affixed to support member 26.

A flicker bar 26 is mounted above the air outlet port 28. The bristles of brush 12 extend beyond the flat portion 30 of the housing 14 to guarantee sufficient interference with surface 13 of xerographic plate 10.

The cover or lid 22 rests on the brush housing 14, thus creating a closed system. The cover is mounted on two pins 32 at either side. Extension springs (not shown) together with pear shaped slots 34 allow the lid 22 to move upwards as the plate 10 enters the cleaning apparatus as shown in FIG. 2. The cover is lifted by the forward motion of the plate 10 against two wedgeshaped earns 21 which are attached to the front of the cover or lid 22. A cam 21 is mounted on either side at the front of the cover. Brush 24 is mounted in the middle of the cover 22. It should be noted that FIG. 1 also shows how the cleaning apparatus would appear after plate 10 has exited therefrom and the cleaning cycle is completed. In this situation, when the trailing edge of plate 10 leaves the brush housing 14, the cover 22 is forced down onto the brush housing flat portions 30 by the action of the extension springs. The stationary brush 24 now inter-feres and enmeshes with the rotating brush 12 forming a nip (contact area) 19 between the two brushes. If the brush 12 is kept running for approximately 2 or 3 seconds after the plate 10 has passed through, a self-cleaning action on the stationary brush 24 is accomplished without the requirement of additional cleaning mechanisms.

In FIG. 2, stationary brush 24, made for example from nylon bristles, is deflected by the leading edge of plate 10. As the plate 10 passes between the lid 22 and the brush housing 14, the back 11 of the plate is wiped clean of any residual toner deposited therein by brush 24.

it is obvious, of course, that as plate 10 is passing through the cleaning apparatus, rotating brush portion 12 cleans off the residual toner from surface 13.

The present invention also minimizes toner leakage during the cleaning process. The airinput will take place only between surface 13 of plate 10 and the top portion 30 of the brush housing 14. This arrangement provides a predetermined air flow and represents a means of minimizing toner leakage. During a cleaning cycle, the following relations prevail: Rotating brush 12 interferes with the flicker bar 26 thus creating an air flow barrier. The vacuum at the bottom of the housing 14 still tends to draw air that wants to pass between the flicker bar 26 and the bristles of brush 12. However, the multitude of bristles on the rotating brush 12 counteracts this tendency by pumping the air into the opposite direction. The result is that maximum vacuum occurs on the side where the air flow is not restricted, i.e., on the right-hand portion of housing 14 at the side where plate 10 enters the cleaning apparatus. With no air flow restriction and maximum vacuum, maximum intake is achieved. Since the maximum air intake happens at the very gap where the toner would normally (with no-vacuum) be centrifuged out of the brush housing 14,v the air flow provides a sealing cushion and carries the toner down into the air outlet port 28.

The material of brush 12 may comprise the materials set forth in the aforementioned U. S. Pat. No.

While the invention has been described with reference to its preferred embodiment, it will be understood by those skilled in the art that various changes may be made and equivalents substituted for elements thereof without departing from the true spirit and scope of the invention. In addition, many modifications may be made to-adapt a particular situation or material to the teachings of the invention without departing from its essential teachings.

What is claimed is:

1. Apparatus for cleaning opposite surfaces of a plate member comprising:

a first brush member adapted for rotation about the central axis thereof for cleaning a first surface of a plate member,

a second brush member supported for movement in a direction substantially normal to the surface of said cylindrical brush member for cleaning a second surface of said plate member,

means normally biasing said second brush member into contact with said first brush member to form a nip therebetween, and

means for rotating said first brush member about said central axis to clean said second brush member in said normally biased position and to clean said first surface of said plate member as it is advanced through said nip.

2. The apparatus as defined in claim 1 wherein said first surface is the surface of photoconductive insulator and said second surface is the surface 'of a conductive substrate, said photoconductive insulator overlying said conductive substrate.

3. The apparatus as defined in claim 2 wherein said first brush member is partially enclosed in a housing, said housing including a cylindrically shaped portion disposed coaxially to said first brush member and at least one flat portion, means interposed between said first brush member and said cylindrically shaped portion for restricting air flow in one side of said housing, and means for introducing an air flow into said housing whereby maximum air intake occurs on the side of the housing where the air flow is not restricted.

4. The apparatus as defined in claim 3 wherein said plate member enters the cleaning apparatus at the side of the housing where maximum air intake occurs, the plate member being separated from said flat portion of said housing by a gap, maximum air intake at said gap causing particulate material removed from said first surface of said photoconductive insulator to be entrained within said housing.

5. Apparatus for cleaning opposite surfaces of an electrophotographic plate member comprising:

' a first brush member of cylindrical configuration adapted for rotation about the central axis thereof for cleaning the photoconductive surface of said plate member,

a second brush member for cleaning the surface of said electrophotographic plate member opposite the photoconductive surface thereof,

means supporting said second brush member for movement in a direction substantially normal to the central axis of said first brush member,

means operatively associated with said second brush member for normally biasing said second brush member into contact with said first brush member,

means for advancing said electrophotographic plate member between said first brush member and said second brush members, said biasing means biasing said second brush member and said electrophotographic plate member in a direction toward said first brush member, and

means for rotating said first brush member about said central axis, the photoconductive surface of said electrophotographic plate member supported in contact therewith and said second brush member, in its normally biased position, being cleaned by the rotating first brush member. 

1. Apparatus for cleaning opposite surfaces of a plate member comprising: a first brush member adapted for rotation about the central axis thereof for cleaning a first surface of a plate member, a second brush member supported for movement in a direction substantially normal to the surface of said cylindrical brush member for cleaning a second surface of said plate member, means normally biasing said second brush member into contact with said first brush member to form a nip therebetween, and means for rotating said first brush member about said central axis to clean said second brush member in said normally biased position and to clean said first surface of said plate member as it is advanced through said nip.
 2. The apparatus as defined in claim 1 wherein said first surface is the surface of photoconductive insulator and said second surface is the surface of a conductive substrate, said photoconductive insulator overlying said conductive substrate.
 3. The apparatus as defined in claim 2 wherein said first brush member is partially enclosed in a housing, said housing including a cylindrically shaped portion disposed coaxially to said first brush member and at least one flat portion, means interposed between said first brush member and said cylindrically shaped portion for restricting air flow in one side of said housing, and means for introducing an air flow into said housing whereby maximum air intake occurs on the side of the housing where the air flow is not restricted.
 4. The apparatus as defined in claim 3 wherein said plate member enters the cleaning apparatus at the side of the housing where maximum air intake occurs, the plate member being separated from said flat portion of said housing by a gap, maximum air intake at said gap causing particulate material removed from said first surface of said photoconductive insulator to be entrained within said housing.
 5. Apparatus for cleaning opposite surfaces of an electrophotographic plate meMber comprising: a first brush member of cylindrical configuration adapted for rotation about the central axis thereof for cleaning the photoconductive surface of said plate member, a second brush member for cleaning the surface of said electrophotographic plate member opposite the photoconductive surface thereof, means supporting said second brush member for movement in a direction substantially normal to the central axis of said first brush member, means operatively associated with said second brush member for normally biasing said second brush member into contact with said first brush member, means for advancing said electrophotographic plate member between said first brush member and said second brush members, said biasing means biasing said second brush member and said electrophotographic plate member in a direction toward said first brush member, and means for rotating said first brush member about said central axis, the photoconductive surface of said electrophotographic plate member supported in contact therewith and said second brush member, in its normally biased position, being cleaned by the rotating first brush member. 